Circuit controlling device



Feb. 23, 1943. T, VAN ETAL 2,312,243

CIRCUIT CONTROLLING DEVICE Filed July 1, 1940 2 Sheets-Sheet 1 4 5 rw Ma c "I "m i xa 10 g n a6 1 a0 I l] O [Q l l\:@

CW2 @Xm'mvw "05. W 222 850. mm, 2332mm @WNM Feb. 23, 1943. c. T. EVANS ETAL CIRCUIT CONTROLLING DEVICE 2 Sheets-Shet 2 Filed July 1, 1940 22m @1 WMM @OQYWMQM Patented Feb. 23, 1943 CIRCUIT CONTROLLING DEVICE Clarence '1. Evans, Wauwatosa, and Paisley B.

Harwood and Forrest C. McNicol, Milwaukee,

. Wis., assignors to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Application July 1, 1940, Serial No. 343,366

Claims.

This invention relates to circuit. controlling devices and while not limited thereto is particularly applicable to manually operated reversing switches for use in motor control systems which employ an electromagnetically operated main switch for establishing and interrupting power connections for the motor.

The invention has among its objects to provide an enclosed manually operated reversing switch for systems of the aforesaid character having safety means associated therewith for preventing operation of the reversing switch except upon opening of the electromagnetically operated main switch.

Another object is to provide a reversing switch of the aforesaid character having safety means associated therewith which insures opening of the main switch upon opening of a door or cover associated with the enclosing casing of the reversing switch.

. Another object is to provide safety means of the aforesaid type which is simple and rugged in construction and exceedingly safe and reliable inoperation. L

Various other objects and advantages of the invention will hereinafter appear.

The accompanying drawings illustrate an embodiment of the invention which will now be described, it being understood that various modifications may be made in the embodiment illustrated without departing from the spirit and scope of the appended claims.

In the drawings:

Figure l is a front elevational view of an enclosed reversing switch embodying the invention, a door for the enclosing casing of the switch beint; shown in open position;

Fig. 2 is a fragmentary sectional view on line 2-2 of Fig. 1;

Fig. 3 is a side elevational view of certain of box shaped enclosing casing 3 having a front cover or door I which is hinged at 5. Reversing switch 2 is carried by an insulating panel 6 which is mounted upon the rear wall of casing 3 and said switch includes an operating shaft I which carries a pair of upwardly extending insulated contact fingers 8-8 and a pair of downwardly extending insulated contact fingers 9-9. Shaft I is rotatably supported at opposite ends by bearing members I0III mounted upon the front face of insulating panel 6 and said panel also carries a plurality of stationary contacts I I, each of which is associated with one of said contact fingers. As is apparent from Figs. 2 and 3, the contact arrangement is such that when either pair of contact fingers 88 or 9-9 is moved into circuit closing position the other pair of contact fingers is moved into circuit opening position.

As shown in Fig. l, the right hand end of shaft 1 has a lever I3 fixed thereto which is operatively connected to a snap operating mechanism I I by a pin I5 fixed to the free end of said lever. The operating mechanism I4 is carried by a forwardly extending U-shaped supporting bracket I6 securedto the front face of panel 6 and said mechanism includes levers I1 and I8 and an over-center spring I9. Lever I! is U- shaped and the side arms thereof straddle bracket I6 and are pivoted at an intermediate point upon a pin 20 mounted adjacent the front end of bracket I6. Lever I8 is arranged between the side arms of bracket I6 and the same is provided with spaced side projections 2| having openings therein for receiving pivot pins 22 fixed to the side arms of said bracket. Pivot pins 22 are spaced inwardly with respect to pivot pin 20 and are aligned with shaft 1. Lever I8 is provided with a projecting arm 23 having an opening therein for receiving the pin I5 on lever I3 and the side projections 2I of said lever are recessed as shown at 24 to receive a stop pin 25 mounted upon bracket I6. As is apparent from Figs. 2 and 3, stop pin 25 limits movement of lever I8 in opposite directions between the positions illustrated in Figs. 2 and 3. The over-center spring I9 has one end connected to a pin 26 mounted upon the inner end of lever I1 and the opposite end of said spring is connected to a. pin 21 carried by lever I8 and located intermediate the pivot pins Hand 22. The side arms of bracket I6 are recessed as shown at 28 to receive pin 26 and said pin engages within said recesses t o limit movement of lever I1 in opposite direc tions, as shown in Figs. 2 and 3.

With lever I! in the position shown in Fig. 2 the axis of spring I9 is located to the right of pivot pins 22 and said spring thus acts to bias lever I8 in a clockwise direction to hold contact pins 49 which is secured to fingers 9 in circuit. opening position. With operating lever IT in the position shown in Fig. 3 the axis of spring I9 is located to the left of pivot 2| and lever i8 is thusabiased to move in a counterclockwise direction to hold contact fingers 9 in circuit closing position and contact fingers 8 in circuit opening position. As is app rent, when lever I! is moved in. either direction between the positions illustrated in Figs. 2 and 3 the axis of spring 2| is moved across the axis of pivot pins 22 to effect operation of shaft 1 and its associated contact fingers with a snapaction.

The above described switch mechanism is provided with an operating handle 30 which is mounted upon the outside of door 4 and is associated with a crank plate 3| mounted upon the inside of said door. As shown in Fig. 2, crank plate 3| is provided with a hub projection 32 which is journaled within an opening extending through door 4 and through an indicating plate 33 fixed to the front face of said door. Handle 39 is secured to hub projection 32 by a screw 34 and crank plate 3| has a drive pin 35 fixed thereto which is spaced'with respect to said hub projection and engages within a channel member 36 fixed to the front end of lever l1. Upon movement of handle 30 into Rev. position indicated in Fig. 4 drive pin 35 acts to move the reversing switch mechanism into the position shown in Fig. 3. Upon movement of handle 36 into the For. position shown in. Fig. 4 drive pin 35 acts to move the reversing switch mechanism into the position shown in Fig. 2. -As shown in Figs. 1 and 2 an'angle member 31 is secured to the rear face of door 4 and the upper end of crank plate 3| cooperates with said member to'limit movement of handle 30 in opposite directions beyond the extreme positions illustrated in Fig. 4'.

The above described reversing switch has two normallyclosed auxiliary switches 39 and 39 associated therewith, such switches being mounted upon insulating panel 6 and being arranged below the abovedescribed reversing switch mechanism. Auxiliary switch 38 is provided with push button operating means. which interlocks with crank plate 3| to'prevent operation of the reversing switch except upon opening of said auxiliary switch. Auxiliary switch 39 is provided with operating means which is associated with door 4, such operating means providing for opening of said auxiliary switch upon door.

More specifically each of the auxiliary switches with a supporting bracket the front face of insu1atins base 6 by a screw 4|. Said brackets are each provided with forwardly extending parallel side portions 42-42 having overlapping projections on the front end thereof which are drilled to 38 and 39 is provided receive a switch operating rod 43. Each-of the operating rods 43 has a stop projection 44 formed on the rear end thereof for engaging the front end of its associated bracket 49, and each of said operating rods also has a on the rear end thereof which engages within an opening in a spring thrust member 45. Also each of the operating rods 43 is biased to move forwardly by a coil spring 41 which is held under compression between its associated thrust member 46 and the rear end of its associated brack- As shown in Fig. 5, auxiliary switch 38 is proopening of said pin extension 45 .held in the position shown .ber 55 to effect opening extension 62 on crank vided with a movable bridging contact 59 which is guided between the side portions 42 of its associated bracket 40 and is movable upon the pin extension 45 of its associated operating rod 43. Bridging contact 50 is biased to move forwardly upon pin projection 44 by a spring 5| which is held under compression between said bridging contact and a guide member 52 which rides upon thrust member 46 and is slidably mounted upon bracket 40. Bridging contact 59 cooperates with contacts 53-53 which are arranged in front of said bridging contact and are carried by contact posts 54 securedto the front face of insulating panel 6.

The parts of auxiliary switch 38 are normally in Fig. 5. As shown a pair of stationary in this figure stop projection 43 is normally held in engagement with the front end of bracket 40 under the action of spring 41 and contact 50 is yieldingl'y held in engagement with its cooperating stationary contacts 53 un der the action of spring 5|. As is apparent from Fig. 5, upon inward movement of operating rod 43 against the action of spring 41 stop projection 44 engages bridging contact 59 to move the same out of engagement with its cooperating stationary contacts 53.

Auxiliary operating member 55 switch 33 is provided with a manual which is slidably mounted within a bushing 56 secured within an opening Y in a well 5'! provided in the front face of door 4. Operating member 55 has an enlarged head 58 .on the front end thereof, and said operating member is biased to move forwardly by a spring 59 which is held under compression between said head and cover 4. Operating member 55 also has a threaded extension 69 of reduced diameter on the inner end thereof which carries a cylindrical stop 6|. Stop 6| engages the inner end of bushing 56 to limit outward movement of operatin member 55 under the action of spring 69 and said stop also cooperates with an offset extension 62 on the'lower end of crankplate 3|. An insulating push member 63 is secured to the inner end of threaded extensionfifl for engagement with the front end of operating member 43 of auxiliary switch 38.

' As is apparent from Fig. 2, when door 4 is in closed position operating member 55 is movable inwardly to effect opening of auxiliary switch 38. Also as is apparent from Figs. 1 and 4, when operating handle '34 is in either of its extreme positions the same is normally locked against movement out of such position by engagement of stop 8| with the offset extension 62 on crank plate 3|. However, upon depression of operating memof auxiliary switch 38 stop 6| is moved out of the path of the ofiset 3| to permit movement of operating handle 39 between extreme positions. During movement of operating handle 33 between extreme positions extension 82 on crank plate 3| is located in front of stop member 8| to thereby prevent reclosure of auxiliary switch 39 until full movement of said operating handle into one or the other of its extreme circuit closing positions.

Auxiliary switch 39 is provided with a movable bridging contact 64 which isguided between the side portions 42 of its associated bracket 49 and is movable upon the pin extension 45 of its associated operating rod 43. Bridging contact 64 is biaser to move inwardly toward spring thrust member 46 by. a spring 65 which is held under compression between said contact and stop pro- 44 on operating rod 1 jection u. Bridging contact :4 cooperates with a pair oi" contacts 66-66 which are arranged to the rear of said bridging contact and are carried by contact posts 61 secured to the front face of insulating panel 6.

Auxiliary switch 36 is controlled by an operating member 68 which is secured within a bushing 69 mounted within an opening in a well 51 in the front of door 4. The inner end of operating member 68 is provided with a threaded extension ll of reduced diameter which carries an insulating push member H for engaging the front end of operating member 43 of the auxiliary switch 39. Whencover 4 is in closed position push member 1| acts to hold the auxiliary switch 39 in the circuit closing position shown in Fig. 6. With the parts in the position shown in Fig. 6 bridging contact 64 is yleldingly held in engagement with its cooperating stationary contacts 66-66 under the action of spring 65. Upon opening of cover 4 to expose the reversing switch mechanism 2 push operating member II is moved out of engagement with rod 43 of auxiliary switch 33 and as is apparent said switch is then moved to circuit opening position under the action of spring 41. I

Referring now to Fig. 7 the same illustrates the circuit connections of a control system embodying the above described reversing switch 2. This figure illustrates a motor M to be supplied with current from a 3-phase alternating current supply circuit indicated by lines L L L The system includes a normally open electroma netically operated line switch 14 for establishing circuit from said supply lines to reversing switch 2, and as shown said reversing switch is arranged to selectively control forward and reverse power connections between said line switch and motor M. Line switch 14 is provided with' an operating winding 14, and as hereinbefore set forth said operating winding is controlled by the auxiliary switches 36 and. 39 associated with reversing switch 2, a normally open start push button and a normally closed stop push button 16 and also by normally open auxiliary contacts l4 associated with said line switch. I

Assuming that door 4 of reversing switch 2 is in closed position and that the operating handle 30 of saidreversing switch is locked in one of its extreme circuit controlling positions. auxiliary switches 38 and 39 are then in circuit closing position and upon depression of start push button 15 the operating winding [4 of line switch 14 is connected across lines L, L' by a circuit extending through said start push button, through stop push button 16 and auxiliary switches 38 and 39. Upon response of line switch I4 the auxiliary contacts 14* thereof shunt the start, push button 15 to maintain operating winding 14* energized upon release of said start push button. As hereinbefore set forth, before reversing switch 2 can be moved out of either of its extreme circuit controlling positions it is necessary to depress operating member 65 and thereby open auxiliary switch 38. Opening of auxiliary switch 38 interrupts the maintaining circuit for operating winding H to insure opening of line switch I4 during manual operation of reversing switch 2. Also upon opening of door 4 auxiliary switch 39 is opened to interrupt the maintaining circuit for line switch 14 and thereby insure opening of said line switch until said cover is returned to closed position. As is apparent, start push but.- ton I5 is operative to effect reclosure of line switch I4 only upon reclosure of auxiliary control switches 33 and 39.

What we claim as new and desire to secure by Letters Patent is:

1. In a control system for electric motors, in combination, an electromagnetically operated line switch, a manual reversing switch movable in opposite directions between given extreme circuit controlling positions to selectively control forward and reverse power connections between said line switch and the motor, an enclosure for said reverslngswitch having an openable cover, and means associated with the cover of said en closure for insuring deenergization of said line switch prior to movement of said reversing switch out of either of its circuit controlling positions and for also insuring deenergizatlon of said line switch upon opening of said cover.

2. In a control 'system for electric motors, in

combination, an electromagnetically operated line switch, a reversing switch movable in opposite directions between given extreme circuit controlling positions to selectively control forward and reverse power connections between said line'switch and the motor, an enclosure for said reversing switch having an openable cover, a manual operating element for said reversing switch mounted upon said cover, a device carried by said cover for normally locking said operating element to prevent operation of said reversing switch out of either of its extreme circuit controlling positions, said device having manual releasing means associated therewith, means associated with said manual releasing means for insuring opening of said line switch upon release of said locking device, and means associated with said cover for insuring opening of said line switch upon opening of said cover. I

3. In combination, a manual control switch movable in opposite directions betweengiven extreme circuit controlling positions, an enclosing casing therefor having a cover which is openable when said switch is in either extreme circuit controlling position and means for controlling power connections to said switch, said means insuring interruption of power connections to said switch prior to movement of said switch out of either of its extreme circuit controlling positions and also insuring interruption of power connections to said switch upon opening of said cover.

4. In combination, a manual control switch movable in opposite directions between given extreme circuit controlling positions, an enclosing casing therefor having an openable cover and means for controlling power connections to said switch including two normally closed auxiliary control switches, each being effective upon open' ing to interrupt power connections to said switch, one of said auxiliary switches being mechanically interlocked with said control switch to provide for opening thereof prior to movement of said control switch out of either of its extreme circuit controlling positions and the other of said auxiliary switches being associated with said cover to provide for opening thereof upon opening of said cover. I

5. In a motor controller, in combination, a reversing switch for the motor movable in opposite directions between given extrem circuit making positions, an enclosing casing therefor having an openable cover, an operating handle for said switch mounted upon said cover and releasably connected to said switch to permit opening of said cover, and means for controlling power connections to said switch including two normally closed ing switch, and a auxiliary control switches mounted within said enclosing casing and each being eifectiveupon opening to interrupt power connections to said switch, one of said auxiliary switches being mechanically interlocked with said control switch to insure opening thereof prior to movement of-- said control switch out of either of its extreme circuit controlling positions and the other of said auxiliary switches being associated with said cover to provide for opening thereof upon opening of said cover.

6. In a motor controller, in combination, a reversing switch for the motor movable in opposite directions between given extreme circuit making positions, an enclosing casing therefor having an openable cover, an operating handle for said prior to movement of said reversing switch out of either of its extreme circuit controlling positions and for also insuring deenergization of said line switch upon opening of said cover.

'7. In a motor controller, in combination, a reversing switchior the motor movable in opposite directions between given extreme circuit making positions, an enclosing casing therefor having an openable cover, an electroresponsive line switch for establishing power connections to said reverspair of normally closed auxiliary control switches mounted within said enclosing casing and each being effective upon opening to deenergize said line switch, one oi; said auxiliary switches being mechanically interlQBked with said reversing switch to insure opening thereof prior to movement of said control switch out of either of its extreme circuit-controlling positions and the other of said auxiliary switches being associated with said cover to insure opening thereof upon opening of said cover.

8. In a motor controller, in combination, a manual reversing switch for the motor movable in opposite directions between given extreme clrcuit making positions, an enclosing casing therei or having an openable cover, an electroresponsive line switch for establishing power connections to said reversing switch, a pair of normally closed auxiliary switches mounted within said enclosing casing and each effective upon opening to deenergize said line switch, a member carried by said cover and having means associated therewith for normally locking said reversing switch to prevent operation thereof when the same is in either of its extreme circuit controlling positions, said member being movable out of a given normal position to release said reversing switch and to also efiect opening of one of said auxiliary control switches, and means associated with said cover for opening the other of said auxiliary control switches upon opening of said cover.

9. In a motor controller, in combination, an electromagnetically operated line switch, a manual reversing switch movable in opposite directions between, given extreme circuit controlling positions to selectively control forward and reverse power connections between said line switch and the motor, an enclosure for said reversing switch having an openable cover, means a sociated with the cover of said enclosure for insuring deenergization of said line switch prior to movement of said reversing switch out of either of 'its extreme circuit controlling positions, and means associated with the cover of said enclosure for insuring deenergization of said line switch upon opening of said cover.

10. In combination, a control switch movable in opposite directions between given extreme circuit controlling positions, an enclosing casing therefor having an openable cover, an operating handle for said switch mounted upon said cover and releasably connected to said switch to permit opening of said cover when said control switch is in either of its extreme circ'iit controlling positions, an electroresponsive line switch for establishing power connections to said control switch, means associated with said cover for controlling said line switch to insure opening thereof prior to movement of said control switch out of either of its extreme circuit controlling positions, and means associated with said cover for insuring deenergization of said line switch upon opening of said cover. 

